At present, dome-shaped or kettle-type cooking apparatus is well known. Such apparatus has a metal base and dome shaped lid, and burns charcoal briquettes to supply the heat required for cooking. In use, the metal dome and especially the metal base nearest the heat source heats up, resulting in reduced efficiency and reduced portability of the apparatus.
An attempt was made to address these problems with a number of developments. In this regard, attention is specifically drawn to patents WO 00/02474, as well as U.S. Pat. Nos. 5,406,930, 5,588,420 and 5,197,379. Previous attempts at insulating the base of the cooking apparatus have utilised insulating material such as fibreglass wool. This method of insulation has a number of disadvantages, the first being that the insulating material increases the overall weight of the cooking apparatus, reducing portability. A second disadvantage is that these insulating materials tend to degrade over time, and may disperse into the air, contaminating the food being cooked. A third disadvantage of these insulating materials is that when they get wet, possibly through standing outside in the rain, their insulating properties vary and their weight increases significantly.
Another method of insulation is the creation of “dead air” spaces in which air or insulating material has been trapped in enclosures in which the airflow has been restricted. This method of insulation has a number of disadvantages. A first disadvantage is that it effectively requires more material to construct. Secondly, it is more complex and therefore more costly to produce. Finally, this method of insulation results in intense heat build-up in the enclosures, dictating the use of heavy materials such as metal for the construction of the apparatus, increasing the weight of the cooking apparatus and further reducing it's portability.